File was build for x86_64 which is not the architecture being linked (arm64)

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I've build OpenCV 3.2.0 with contrib for iOS. Everything works nice, but when I want to use the MultiTracker class (from libopencv_tracking) and run the project on a physical device i get this warning:

Ignoring file /libopencv-tracking.dylib, file was build for x86_65 which is not the architecture being linked (arm64) Because the project can't be linked with the library, it can't find reference to that class, hence some errors.

If I run in a terminal 'lipo -info libopencv_tracking.3.2.dylib' i see that the architecture is x86_64 and i have no Idea why. I never explicitly set the architecture to be like this.

I really searched the last day and none of the answers helped me. Thank you!